Radio Frequency (RF) receivers have finite instantaneous dynamic range (IDR), which limits their ability to receive weak signals in the presence of strong signals. The weakest link in RF communications is typically the analog-to-digital converter (ADC). However, analog components such as amplifiers can limit performance as well. While automatic gain control (AGC) allows a system to operate at different input power levels, it does not improve the IDR.
Unchecked interference from strong signals may either de-sense the receiver or saturate it in ways that cannot be filtered or counteracted in digital post-processing. Beyond the blunt force AGC and front-end attenuation approach, more focused existing techniques for protecting RF receivers involve analog filtering at the front end. These analog filters are often configured as band-reject or notch filters. In addition active cancelers may also be used in cases in which a tap or a sample of the interference is available.
The modern electromagnetic (EM) environment is both dense and dynamic. This is particularly true for mobile platforms. In some applications, some form of EM spectral monitoring is paired with tunable or switched filters or blanking strategies. However, these existing techniques do not provide the optimal combination of fast tuning speed, low loss, linearity, spectral precision, and wide tuning range that is required in certain environments.
A need exists, therefore, for systems and methods for reducing interference in RF communications that overcome the shortcomings of existing techniques.